Metal materials such as Nitinol and stainless steel are often used in the construction of implantable medical devices. Permanent implantable devices are required to survive under cyclical loading for millions and often times hundreds of millions of cycles. Stress raisers can be created in geometries with large and sharp or abrupt dimensional changes. These stress concentrations can cause difficult-to-predict fatigue failures. The design of component geometry and joining methods is critical to assuring long-term survival.